Transmitting-instrument for electric signaling apparatus



(No Model.) 3 Sheets-Sheet 1. W. J. DUDLEY. TRANSMITTING INSTRUMENT FORELECTRIC SIGNALING APPARATUS.

No. 399,505. Patented Mar. 12, 1889 N PETERS. Phola-Lilhogmphcr.Washingwm a. c.

(No-Model.) a Sheets-Sheet 2.

W. J. DUDLEY. TRANEMITTING INSTRUMENT FOR ELECTRIC SIGNALING APPARATUS.

No. 399,505. PatentedMar. 12, 1889.

Wain/eases, Inventor;

- Wjfluallay,

(No Model.) 3 SheetsSheet 3.

W. J. DUDLEY. TRANSMITTING INSTRUMENT FOR BLNGTNIG SIGNALING APPARATUS.

No. 399,505. Patented-Mar. 12, 1889.

Nv PETERS. Phowullw m ner, Wzshinglon. D. c.

STATES UNITE PATENT OFFICE.

YALTER J. DUDLEY, OF EVERETT, MASSACIlUbE""S, ASSIGNOR TO THE DUDLEYELEC RIC MANI'FACTURING COMPANY, OF COXDORD, YEW

HAMPSHIRE.

TRANSMITTING-INSTRUMENT FOR SPECIFICATION forming part of Letters latentN 0. 399,505, dated March 12,1889.

Application filed July 19, 1888.

T0 ceZl whom it may concern.-

Be it known that I, WALTER J. D UDLEY, of

Everett, county of Middlesex, and State of Massachusetts, have inventedan Improvement in Transmitting-Instruments for Electric SignalingApparatus, of which the fol lowing description, in connection With theaccompanying drawings, is aspecificat-ion, like letters on the drawingsrepresenting like parts.

This invention is shown embodied in a transmitter or instrument forgoverning the transmission of electric impulses over a circuit for thepurpose of o 'ierating individual signaling-instruments or other aiparatus of similar-nature. The transmitter is especially intended foroperating individual signaling instruments such as shown in LettersPatent 2,310, dated May 25, 1885, there being one such instrument ateach of the different stations on a single line, and each instrumenthaving an eleetro-magnet and actuating-armature operated by successiveelectric impulses 3 of proper strength and duration to actuate astep-by-step device, and said magnet also con trolling aunisoning-armature held in position to arrest the stepby-step devicewhile the actuating-currents are being applied and being retainedattrz'teted by residual magnetism be- I tween the succ ,ssive actuating-cu rrents which The cause the actuat ing-armatiire to vibrate. saidunisoningarmature is so adjusted as to be released or retracted upon theap )lication ol' rapidly-alternating currents, such as produced by amagneto-eleetric gtmerator or by a very feeble current of short durationand of opposite polarity to those employed For actuating thestep-lrv-step t'levices, and the signaling-instrument which is placed ineircuit by the step-by-step controlling device at the desired station isalso actuated by the alternating or magnetoelectric currents, which are,however, not powert'ul entmgh to move the fitt-lP-lJX-Sltllactuatingarmature.

lhe transmitting-instrument forming the subject o't this invention isadapted to automatically transmit. a number of actuating currents orimpulses, by which the step-bystep devices of all the signal-controllinginstruments on the circuit are moved. far enough to bring them to theunison position at which Serial No. 280,361. (No motieLl 3 they arearrested by the unisoning-armature, immediately after which thetransmitting'instrument causes an alternating magneto-eurrent or feeblebattery-current of opposite polarity to the actuating-currents to besent over the line for a moment and thus effects the release of all thestep-bystep devices by the unisoning-armatures, after which thetransmittirig-instrument sends a definite number of actuating impulsesby which all the stepby-step devices are. advanced a certain number ofsteps requisite to place the signalinginstrument at the station to becalled in operative condition the said number of steps, placing but onesuch instrument in circuit at atime after the manner well known to thosefamiliar with individual signaling apparatus. All these currents arecaused to be transmit-ted in the proper numberand proper order by asingle movement of the operator, who merely turns a crank about oncearound adial and stops it opposite a number on the dial corresponding tothe station to be called, l said movement of the crank actuating andcontrolling the mechanism of the motor by which the required currentsare transmitted, and the whole operation of sending the call being veryquickly performed.

It is desirable for the best operation of naling-instruments thatcurrents of about the same strength should always be used, and as thedilterent lines of a telephone-exchange are likely to vary widely inresistance, the currents from the same generators or bat teries wouldvary widely in strength in accordance with the wellknown laws unlessmeans were provided for preventing such variation.

The transmitting-instrument forming the subject of this inventioncontains appliances [or evening up the resistance of the different lineswith which the instrument maybe used,

as follows:

Thesignaling-instrumentsand (atrrent-gtae erators are properlyproportioned to t'iperate with lines of the greatest resistance in theexchange.

The transmittirig-instrument has several resistancecoils which, justbefore the transl mitting part of the instrument is operated, are all inthe circuit. The act of turning the ioo crank to set the transmitter inoperation first moves a switch or circuit-changer, by which portions ofsaid resistance are successively removed from the circuit, therebyincreasing the strength of a current which is then put on the line. Anelcctro-Tnagnet is included in said circuit, and its armature isproperly adjusted to be attracted when the current reaches the properstrength for operating the instruments. The lever of the armature of thesaid magnet when thus attracted arrests the circuit-changin g device bywhich the resistance-coils are being cut out, and thus retains the'proper amount of resistance in ci'rcuit until after thesignaling-currents have been transmitted.

The invention also consists in man y combinations and details ofconstruction, which will be hereinafter described, contributing to thecerta ntyand efficiency of operation of the instruments.

Fi ure l is a front elevai ion of a transmittin -instrument embed 1112'this invention a a a portion otthe dlal or front frame-plate beingbroken away to show the parts immediately atth erear of it; Fig. 2, aside clevationof the instrument with a portion of the framework brokenaway to better show the parts at the rear; Fig. 3, a perspective view ofthe mainshaft of the instrument and 'parts directly connected therewith;Figs. 4 to 8, various details to be referred to; and Fig. 9, a diagramshowing the circuits, current generators, and various instruments forcontrolling the circuit and transmission of currents thereof.

The various operative parts are supported on flame-work (shown asconsisting of plates to a" a :ct ).connected by rods or pillars a}, aportion of which are broken away in Fig. 2. The rear plates, a a a aresmaller than the front platea, and may receive a cylindrical casing(indicated in dotted lines at a Fig. 2) to inclose the working parts.For convenience in reference it may be stated that the devices thatdirectly control the circuit are mainly between the plates to a, and themechanism that regulates or governs the movement of said devices ismainly between the plates a a and the devices for automatically eveningup the resistance of the different lines with which theinstrument may beused are mainly between the plates c and a it being understood that eachoperator at the central office of the telephone-exchange is providedwith one of these instruments, which is switched into or connected withany subscribers circuit on which a call is to be made in'the usualmanner.

til another call is to be sent. The said crank 12 is fixed upon a shaft,1), (best shown in Fig. 3,) extending from the front plate, a, to theplate a and at present the mechanism between the plates a and a need notbe referred to. The said shaft 1) has fixed upon it a disk, 0, providedwith ratchet-teeth c, located and spaced with relation to the crank b tocorrespond with the numbers on the dial (t, and being controlled by apawl, pivoted on the front plate, (I, as will be understood from Figs. 1and 2. Thus when the crank I) is turned around in the direction of thearrow to any number on the dial, the pawl prevents the reverse rotationof said crank and its shaft. The said shaft 1; has loose upon it asleeve, (7, which extends through the plate a, and at the front of saidplate has attached to it the main circuit-controlling disk or wheel 6,and at the rear of said plate a the sleeve (Z has connected with it agear, (1, meshingwith a train of wheel-work, (Z (Z (1" (1, terminatingin a regulating device, (1 the purpose of which train is merely toretard and control the speed of movement of the disk 6 when actuated, aswill now be described.

The construction of the regulating device is shown in Fig. 4-,itconsisting of an arm, (1 on the most-rapidly moving arbor (7. of theretarding-train,said arm having at one or both ends a weight, d pivotedor'hung to swing outward under centrifugal force,which may, if desired,be resisted by..a spring, (1

The weight d turns in a cylinder, (1 and as the speed increases the saidweight is thrown outward by centrifugal force,- and thusehas morefriction on the cylinder 61 which preventsfurther increase of speed. Theshaft b isconnected with one end of a spring, f, (see Fig. 5,) the otherend of which is connected with the disk 6 by the pin f as shown in Fig.and in dotted lines, Fig. 2, so that the rotation of the shaft 1) by thecrank 19, as before stated, strains the said spring, which then tends torotate the disk 6 in the same direction, the speedyof rotation of saiddisk"- being controlled by the train (1' (1 &c., asbefore stated. Thepawl 0 in connection with the teeth 0' of the disk 0, retains the shaftI at whatever point it may have been turned to by the operator, thuskeeping the spring f strained, so as to propel the disk e until thelatter is arrested in its normal position by the It will be understoodthat the tension of I the spring f tends to rot-ate the crank b and itsshaft in the direction opposite the arrow,

and if the said crank should be released by the operator before the disk0 was engaged by. the pawl c said crank would fly back rapidly and mightinjure the instrument. To pre- ITO vent this action, the shaft b isprovided with a gear, b meshing with a pinion, U, the arher of which isprovided with a retarding device or governor, I)", (see Fig. 3,) similarto the one controlling the train (7/ (7 &c., be fore described. Thisgovernor permits the shaft 1: and crank 11 to be turned as rapidly asthe operator readily can by hand; but the said governor retards thecrank in case itshould tlybaek in the reverse direction by the action ofthe spring f sufficiently to prevent injury to the ratchet-teeth c andpawl 0 or other parts of the instrument. The disk is arrested at adefinite point, after it has been turned by the spring], by a lockingdevice, consisting of a pawl or hook, g, (best shown in dotted lines,Fig. 1,) that en gages a pin, g, on the disk 6, preventing the rotationof said disk when said hook is in position to engage said pin, as shownin Fig. 1. below the pin-engaging shoulder the hook has a cam-face, gwhich is engaged bya-projection, g, on the disk 0, when the operatorturns the crank 7: once around from any position in which it may be heldby the pawl (1 said projection g striking the cam-face g and lifting thehook g, and thus releasing the disk c, which immediately begins torotate under the stress of the spring f in the same direction that theoperator is rotating the crank 11, but at a lower speed, owing to theaction of the rctarding-t-rain, (l (7 &c. The disk 6 is thus caused tomake one complete rotation after the crank 17 has been turned oncearound wholly irrespective of the particular point on the dial at whichthe crank I) is stopped.

The stop-hook g has a second stop hook, g",

said stop-hook g is engaged with its pin g,

the hook g is retained high enough to permit the pin 9 to pass beneathit, as will be understood from Fig. l; but after the hook g has beenraised and the pin g has passed it, both hooks g g fall in nearer to thecenter of the disk 0, so that if the crank Z) were accidentally turnedbeyond the numbered part of the dial a, so as to begin a secondrevolution, the pin g would be arrested by the hook g thus preventing asecond revolution of the crank b until after the disk 6 had made onecomplete revolution and been arrested in its normal position. \Yhen thedisk c has nearly finished its revolution from the normal startingpointshown in Figs. 1 and 5, the pin 9 engages the under part of the hook-armg and lifts both hooks g 9 before it is arrested by the shoulder on thesaid hook g, and thus pro- I vides for the next operation of the crank12.

In order to further prevent danger of overwinding the spring or ofrunning down the said spring in case the shat t b and parts upon itshould be removed from the frame-work, and consequently't'rom thecontrol of the pawl c and locking devices 9' g", an arm, 72, (see Fig.5,) is pivoted loosely on the shaft b at the side oi. the disk 6, andhas its movement with relation to said disk limited by stops 71 7L2 toabout a quarter of a turn. The end of the arm 72 also stands in the pathof the projection g on the disk c, as shown, in such manner as to permit about one turn and a quarter of the disk (2 with relation to thedisk c: but it in anyway the shaft should be turned farther, the pin gwould engage the arm 71 and carryit forward until arrested by the stop71", when the shaft 1) can turn no Farther without positively carryingthe disk (1 with it. 'It', on the other hand, the disk 1' were in anyway removed from control of the/pawl 0*, the springf would tend torotate the shaft 1) backward with relation to the disk. 6', but in suchbackward movement the pin g would engage the arm I! and carry it alonguntil arrested by the stop 71, when the shaft [1 could move backward nofarther wit-h relation to the disk 6, and consequently the spri ngf willnot be unwound upon such disengagement ot' the pawl The disk 6 (bestshown in Fig. 5) is the direel-current controlling part of theinstrument,and is provided with certain projections which in therotation of said disk co-operate with circuit-controlling springs orkeys to transmit the requisite cu rrents to line.

The actuating currents or impulses by which the step-by-step devices ofthe signal-controlling instruments are moved are governed by a key orcircuit-controlling device, 1;, (best shown in Fig. 5,) consisting of alever pivoted at 71 and provided with a contact, le that cooperates witha stationary contact, 7,2 insulated from the frame-work oi" the machine.The lever 7a is impelled in the direction to close the contacts by aspring, is, but is moved in the direction to separate the contacts bythe projecting parts of the periphery of the disk 0. The said disk 6 isprovided with ahigh projection, c, that stands under the short arm ofthe lever 7; when the said diskis arrested in its normal position, asshown in Figs. 1 and 5, and which then holds the lever 7a in its mostremote position from the contact k and brings another contact-spring, kconnected with said lever into engagement with a contact, 7.1 (see Fig.1,) insulated from the framework of the machine, the purpose of whichcontacts 7; will be hereinafter explained.

hen the disk 6 begins to rotate in the direction of the arrow, Fig. 5,from its normal position, the lever it drops otf from the highprojection e and is acted upon by a number of small alternate notchesand projections, 6 which vibrate the lever with considerable rapidityand thus, by the contacts 1& k transmit a number of actuatingimpulsesthat bring all the step-by-step devices controlled by the cir- (suit tothe lll'llSOl'l-DOll'lt. Beyond the notched part c is a plain part, c,whichkeeps the lever 7;, with t e contacts 71' is, separated, and whilet is part c of the disk is in engagement with the lever 7c theprojection 6. passes over the spring in, which transmits the current bythe bell in that station in which the said bell which theunisoning-armature is operated to release the step-by-step device. Afterthe projection c has passed the spring 777/ and the.

plain part c of the disk has passed the lever k, a number of largenotches and projections, e (see Fig. 1,) arrive in position to actuatethe lever and contacts 10 k by whicha number of comparatively-slowimpulses are transmitted, that actuate the step-by-step devices inunison with great certainty, thus advancing them to the desired point toplace theinstrument at the station to be called in operative condition.A sufficient number of large notches e are provided to advance the stepby-step device as far as may be required to bring thesignalinginstrument at any station into operative condition; but only avcertain number of said notches c are permitted to operate on the key 7cat any-time, the said number being determined inaccordance with theposition to which the lever 19 was turned onthe diala, as follows: Aloose canrsegment, n, is pivotally connected at a with the disk 0, andhas its other end controlled by a pin, 11 on said disk, which permitsthe movement of said segment a between the position shown in full anddotted lines, Fig. 5. In the dotted-lineposition the said segment apermits the notches e to act on the lever 7r, but in the full-lineposition the said segment it engages the lever 10, which is wide enoughfor this purpose, and thus retains the said lever stationary in the sameposition that it is held by the unnotched part c of the periphery of thedisk c. This segment-is controlled by the pin g on the disk 0, whichraises the segment to the full-line position shortly after its pivotedendn has passed the said pin 9 and thus the position of the pin 9 whichdepends on the position to which the crank b is turned and held by thepawl 0 determines the time in the rotation of the disk e that thesegment is thrown out and the lever it removed from control of the teetha. For example, as shown in the drawings, the crank 12 is stoppedopposite the number 6 on the dial, and in this position six of thenotches e will pass by the lever k and cause six vibrations thereofbefore the segment at is thrown out by the pin 9 and the vibration ofthe lever It thus stopped.

If the crank b had been stopped opposite number 1, the segment wouldhave been thus thrown out after. the first notch had passed and acted onthe lever Zr, and if turned to any other number on the dial the saidsegment would be thrown out after the same number of notches had passedthe lever 7r. Beyond the large notches e the disk 6 has a plain portion,a which retains the key is with the contacts k k separated, and at thistime a number of projections, e, (see Fig. 2,) at the rear side of thedisk 6 cooperate with a spring, m, by which the circuit is closedbetween the line and the magnetogenerator and the magnetoelectriccurrents thus transmitted, which ring has been placed in circuit by thestepby-step device. After the plain part has passed the key is and theprojections e have passed the spring m, another series, 6 of smallnotches act on the lever Ir, producing another series of actuating.impulses, by which the step-hystep devices are again brought to theunison-point, thus removing the signaling-im struments at all stationsfrom the circuit. The signaling-instruments'are thus left at theunison-point immediately after a signal has been sent out from thecentral office, which is desirable, as it prevents possibility of any ofthe "signals being operated by calls sent in over the same line to themain oiiice; but as there is possibility that some of the instrumentsmight be thrown out of the unison position in some way in the intervalbetween two signals this final unisoning of the signals by the notches eis not relied upon solely, but the instruments are also acted upon atthe beginning of each transmitting operation by a number of impulsesproduced by the notches 6 sufficient to bring the instruments to theunison-point if the notches 6 should have failed to do so at the end ofthe last transmitting operation, or if they should have in any way beenmoved from the unison-point during the interval which has elapsed sincethe last preceding signal was transmitted. After the notches e" havepassed the key 7c the projection 6' comes to rest under the said key,leaving the contacts k la normally separated and the contacts k isconnected together, this being the only time that said contacts 70 k areconnected.

The circuit-connections and modeof operation of the devices thus fardescribed will be best understood from the diagram Fig, 9.

The subscribers line, grounded at its outer end, as shown at 2, andpassingthrough the various subscribers stations is" S is connected withthe transmitting-instruments at 3, by the devices commonly employed atthe central office of telephone-exchanges, the said connection beingmade with any line on which a station is to be called. The connector 4,by which the instrument is connected with a subscribers line, is itselfconnected in circuit, as shown at 5, with the metallic frame-work of theinstrument, including the shaft b', disk 6, key 76, and contacts k kthereof. The contact 10 insulated from the frame-work, as before stated,is connected by wire 6 with battery 13, connected with the ground at 7,said battery being strong enough to produce the requisite actuatingcurrents in subscribers circuits of maximum resistance. The spring on iseither connected through resistance R with one terminal of the generatorG, the other terminal of which is grounded at 7, or

is connected with one pole of a battery, B,

the other pole of whichis grounded, the said battery being much smallerthan the battery B and having its opposite pole connected to the springat from that of the battery B, conuected with the contact 70 It is verydesirable to provide for connecting either the generator or the batteryB with the spring m, as shown in Fig. 9. The spring m is connected withone pole of the generator G, the other pole of which is grounded, asbefore stated. The contact 7. connects with a branch, 100, groundedthrough the telephonic instrument T.

The operation is as follows: In the normal position the subscribers line2 3 is connected by 4 5 and contacts 7t and wire 100, through thetelephone T with the ground. Vhen the disk e is rotated by the devicesbefore described, the telephone branch 100istirst-disconnected from theline at 7: and the notches e of the disk 6 cause a number of impulses tobe transmitted from the battery 1; over circuit 7 6 k k 5 i 3 2, rapidlyactuating the step-by-step devices at the stations S Then the batterybranch 6 7 is disconnected from the line at k 75" while the blank part cof the disk passes the key It, and at this time the projection 6 makescontact with the spring m, thus sending the current from the generator Gand through resistance R or from the battery B, as may be mostdesirable, from the said spring m to the disk 6 and circuit 5 at 3 2.The weak current of the battery B or the alternating-current of thegenerator G weakened by the resistance R will act to completelyneutralize the magnetism of the stepby-step magnets at the stations andwill thus release their 1111 isoning-stops, as before stated. Then thelargest notchesc will again actuate the key it, controlling the circuitof the battery B at it it as before described, sending a number ofcomparatively-slow impulses of said battery, which number is determinedby the position of the crank b and effect of the pin 9 on the segment a,as before described, and after a sufficient movement to permit themaximum number of notches c that will ever be required to act, theprojection 6 will cooperate with the spring m, while the key 1.: is heldopen by the blank partc of the disk,

thus sending the currents from the generator G over the circuit toactuate the signaling-instrument at that station where suchsignalinginstrument has been put in circuit by the step-by-step device.

It may in many cases be necessary or desirable to render the resistancein circuit about enough so that the battery and generator currents willact with about the same strength i on the sign-aidnstruments in thedifferent ciri cuits of the exchange.

Such evening up of the resistance of the'circuit is automatically leffected by devices which will now be described, being mainly thoseincluded between the frame-plate (L2 a. in Fi certain other devices.(Best shown in Fig.

together with l These devices comprise a number of different The shaft'25 has its bearings in the plates a a, Fig. 2, and is in line with butdisconnected from the shaft Z), as shown in Fig. 3. The said shaft tcarries an arm, 15, having a yielding contact, f (see Fig. 7,) which asthe said arm '1 is rotated makes contact with the studs and before thedisk 6 is released, as before described, the said projection it engagesthe projection i and turns the switch-arm i in the direction to cut outthe various parts of the resistance r. The spring-tube of the contact t(see Fig. 7) and the projection 25 pass through a curved opening in theplate a that permits about a quarter-turn of said parts. Anelectro-magnet, it, one coil only of which is shown in Fig. 2, isincluded in the circuit, and its armature i is so adjusted as to beattracted when the current, which gradually being strengthened byremoval of the resistance, reaches the normal strength at which theinstruments are to be operated. The armature-t has an arm, 5, which,when attracted, engages a toothed piece, t on the shaft 2f, and thusprevents further movement of said shaft and of the switch-arm t themoment as before stated, made yielding, yields and permits the shaft 1)to continue its rotary movement. The switch-arm I" also has a toothedarc, i which is engaged by a pawl, t best shown in Fig. 3, preventingthe said arm from returning to its original position, tmvard which it isimpelled bya spring,

t, and at which it is arrested by a stop, t (See Fig. 2.)

It is necessary that the current of the actuating-battery B should boonthe circuit during the movement of the switch-arm f, by which theresistance of the line is adjusted, in order that its current may beaffected by said resistance, and that the magnet 2 may be operated whenthe current reaches the proper strength. For this purpose the gcarh orany other part carried by the shaft Z1, is provided with acontact-plate, u, that co-opcratcs with a spring, 21-,to connect thebattery l to line through the switch i and resistance r during thatportion of the rotation of the crank I) in which the switch-arm iaccompanies it. As the magnet is in circuit during the subsequenttransmission by the disk c,

its armature would respond to the impulses transmitted by said disk.This would not aiiect the operation of any part; butin order to preventthe rattling noise that would en= sue, a stopping device, it, isprovided that bears against the armature 7"", as shown in Fig. 2, andprevents it from'being retracted as the circuit is broken. It isnecessary, however, for the co-operation of said armature with thenotched piece i that said armature should be, free while the switch-arm25 is making its movement. For this purpose said stop in is connected,as shown in Fig. 3, with an arm, "llf', acted upon by a cam, 21: on theshaft Z), which turns said stop 20 away from the armature tjnst beforethe projection f engages the proj ection ii" of the switch-arm, and saidcam [U2 retains the stop w away from the armature long enough to permitthe arm I" to make its maximum movement.

It is necessary that the switch-arm 2" should start from its originalposition in which all the resistance r is in circuit each time thatthese devicesare set in operation. To insure this result, the pawl t isconnected, as best shown in Fig. 3, with the rock-shaft 1 having an arm,t, engaged by a pin, 1 on the gear b connected with the shaft 1'),before the projection 29* reaches the projection i All these operationstake place in the movement of the crank 71 outside of the graduated partof the dial a at some point in which it is held by the pawl c after itis turned, and during this part of the movement of the arm I) the diskcremains stationary, as it is not released by thepin g acting on thehook until the crank arrives at or nearly at the graduated part of thedial.

The operation of the devices thus far described for automaticallyadjusting the resistance of the line will be readily understood fromFigs. 3 and 9, in which latter-it is shown that the subscribers circuit2 is connected with one terminal of the magnet 25*", the other terminalof which isconnected with the resistance while the switch-arm 73, aswell as the contact-plate 'u, are in electrical connection with theframe-work of themachine represented at in the diagram. This spring a,that co-operates with the contact-plate u,is

connectedby wire 12 with the battery B,

whiehduringthe entire operation of adj ustingtheresistance is otherwisedisconnected from the frame-work of the instrument at k N. hen the crankb is turned-in the direction of the arrow, the projection i firstengages the arm't and trips the pawl permitting the switch-arm t to beturned back to its normal position (shown in Fig. by the spring In thisposition the contact of said switch-arm rests on the stud r, and thewhole of the resistance r is in circuit. Immediately after this thecontact it reaches the spring it and connects the battery B by wires 612 with the frame-work of the machine, including the switch-arm t, andthence through the resistance r to the subscribers circuit. At the sametime the cam engages the arm to and releases the armature t, which,unless. the circuit is one of maximum resistance, will fall back, owingto the resistance. At the. same moment the projection 15" will engagethe projection 2'", and begin to move the switch-arm t in the directionto cut out the successive portions of resistance between the differentstuds r W, &c., and when by such graded reduction of the resistance thecurrent arrives at the desired strength the magnet 29' will attract itsarmature, and will arrest the switch-arm by engagement of t i andprevent the further reduction of resistance. The projection II willspring past the projection i and the shaft Z) continue its fartheronward movement unaccompanied by the shaft 2 and switch-arm t. Shortlyafter, the cam it will disengage the arm in, and the lock 10 will bebrought ,up by its spring to to engage the armature If and prevent itresponding to the currents. After this the crank 12 will be carried onto the number on thedial a of the station to be called, having releasedthe disk 6 just before it arrives at the numbered part of the dial, sothat the said disk begins its movement before the arm 1) comes to restatthe proper number on the dial.

If the operator should by accident carry the arm Z) beyond the desirednumber on the dial a, it cannot be turned back, and the operator mightattempt to carry it wholly arou n d again. This would be prevented bythe stop g and the crank I) when released wouldfall back and be held bythe pawl c opposite the zero-point on the dial. Thiswould cause thestep-by-step device of the signaling-hr strument to be turnedwhollyaround before the generator-current was applied by the sprin m,and consequently no station-signal would be in circuit and no falsealarm given. The operator would consequently have to wait until the disk6 had finished its rotation and thus raised the stop-hook g, so that thecrank I) could be again operated and this time stopped at the properpoint.

In actual practice it does not require over ten seconds for a completerotation of the disk 6, so that but little time is thus lost.

Severalof the devices herein described are not absolutely essential tothe operation of thetransmitter, but all contribute to render theinstrument convenient and efficient in op eration, and it is to beunderstood that the omission of non-essential devices or variations intheir construction,not changing the essential mode of operation, is nota substantial departure from the invention herein shown and described.

The shaft 1) is the actuating and controlling shaft For the cntireinstrinnent, and the disk 2 the e'ircuit-controlling part, and itsvarious notches and projections constitute the signaling-surface, which,in conjunction with thecontact springs and keys eo-operating with it,determine the character of the current and of the interruptions of thecurrent by which the required efifect is produced on thesignal-receiving instruments, and it is obvious that: the mechanicalconstruction of these parts might be varied and equivalent devicesemployed without depart i n from the invention.

I claim 1. The cont rol ling-shaft movable to and held in differentpositions, combined with a current-interrupter controlled by the saidshaft, and a lock for said current-intcrrupter and areleasirig-projection therefor connected with the said shaft, wherebythe said interrupter is released and produces a number of electricimpulses dependent on the point at which the said shaft has beenstopped, substantially descri bed.

2. The main-line and two branch circuits containing sources of differentkinds of electric currents-as, for instance, a battery andmagnetc-generatorcombined with a transmitting-instrum ent comprising amovable signaling-surface having a definite cycle of movement, the sameat each operation, and an actuator therefor, and circuit-controllincontacts operated thereby during said continuous movement,controllingthe connection of said branches with the main line,substantially as and for the purpose described.

3. The main-line and three branch circuits, one containing a battery,one a magneto-generator, and thetihird containing a source of currentsof opposite polarity to that of the said battery, combined with atransmittinginstrun'ient conu'nising a movable signalingsurtaee having adefinite cycle of movement, the same at each operation, and actuatortherefor and eircuit-controlling contacts operated thereby, by which thesaid branches are all eonnectml to line each at different times during asingle {)lltlftillUll of said signaling-snrfaee, substantially as andfor the purpose described.

-:t. The actuating-shaft and wheel having a sign alin g-surface loosethereon and actuati n gspring connecting said shaft and wheel, combinedwith a stop for said wheel released by said actuating-shaft and a secondstep connected with said wheel-stop and operated thereby, the secondstop being arranged to ar rest the actuatirig-shaft, except when thefirst is engaged with the said wheel, substantially as descriljied.

The actuating-shatt and transmittingwheel hmse thereon, combined with anactit ating-spring connecting the said shaft and wheel, an arm loose onsaid shaft, and stops -co-operating with said arm on said wheel,

and a projection co-operating with said arm connected with saidactuating-shaft, substantially as and for the purpose described.

6. The actuating-shaft and disk fixed thereon, having a portion of itsperiphery provided with ratchet-teeth, cr'm'ibincd with a pawl to engagesaid teeth, a circuit-controlling wheel loose on said shaft, and anactuating-spring connecting said shaft and wheel, and a stop for saidwheel operated to release the wheel by the movement 01 the shaft,substantially as described.

'7. The actuating-shaft movable to and held in different positions,combined with a circuitcontrolling wheel having a signaling-surface andelectric contacts controlled thereby, a segment connected with saidwheel, and a projection eo-o wrating with the said seg ment connectedwith the actuating-shaft, whereby the said segment is moved to prevent aportion of the signaling-surface from operating the contacts,substantially as described.

8. The combination of themain circuit and generatm' of electricitytherein, with resistance in said circuit and contact-points betweendit't'erent portions of said resistance, a switch movable over the saidcontact-points, and an eleetro-magnet included in said circuit, and anarmature therefor which engages and arrests the said switch when theattraction of the magnet overcomes the retract-or ol the armature,substantially as described.

fl. The combination of the actuating-shaft, with a movable switchengaged by said shaft, and an electro-magnet and its armature thatarrests the said switch, a lock that retains the said switch in theposition to which it has been. moved, and a releasing device for saidlock operated by said shaft before the latter engages the said switch,substantially as and for the purpose iilescribed.

ill. The combination of the actuating-shatt with a movable switchengaged by said shaft, and an clcetro-magnet and its armature thatarrests the said switch, a lock that holds the said armature up to itsmagnet, and an actuator for said lock on said shaft by which thearmature is released while the switch is engaged by the shaft,substantially as and for the purpose described.

11. The main circuit and transmitting instrumen t 1nrovidcd with acircuit-eontrolling wheel and electric contacts operated thereby,combined with a branch circuit containing a source of electricity whichis connected to said main circuit during the movement of said wheel, andanother branch containing a telephone which is connected to said maincircuit by the wheel-controlled contacts when said wheel is arrested inits normal position, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subseribin g witnesses \YALTER J. DUDLEY.

Witnesses:

.los. 1. Lrvnnnonn, M. E. HILL.

